Chapter 6 Key Terms

• The totality of an organism's chemical reactions
• Transforms matter and energy, subject to the laws of thermodynamics

Begins with a specific molecule and ends with a product, and each step is catalyzed by a specific enzyme

Release energy by breaking down complex molecules into simpler compound

A catabolic pathway in which glucose is broken down in the presence of oxygen

Consume energy to build complex molecules from simpler ones

The study of how energy flows through organisms

• Capacity to cause change 
• Can be converted from one form to another

Energy associated with motion

Energy that matter possesses because of its location or structure

Potential energy available for release in a chemical reaction

The study of energy transformations

Energy and matter cannot be transferred between the system and its surroundings

• Energy and matter can be transferred between the system and its surroundings
• Ex: Organisms

• The energy of the universe is constant 
• It can be transferred and transformed, but it can't be destroyed

Every energy transfer or transformation increases the entropy (disorder) of the universe

Energy that can do work when temperature and pressure are uniform, as in a living cell

• Spontaneous process
• Can be harnessed to perform work

• State of maximum stability
• A process is spontaneous and can perform work only when it is moving toward equilibrium
• Metabolism is never at equilibrium

Proceeds with a net release of free energy and is spontaneous (-ΔG)

Absorbs free energy from its surroundings and is nonspontaneous (+ΔG)

• The use of an exergonic process to drive an endergonic one
• Used by cells to manage energy resources
• Mediated by ATP

Chemical agent that speeds up a reaction without being consumed by the reaction

The initial energy needed to start a chemical reaction

The reactant that an enzyme acts on

Formed after the enzyme binds to its substrate

• The region of the enzyme where the substrate binds
• Can lower the activation energy barrier

• Nonprotein enzyme helpers
• May be organic or inorganic

• An organic cofactor that is required by an enzyme
• i.e vitamins

Something that binds to the active site of an enzyme preventing the substrate from binding

• Bind to a part of the enzyme that isn't the active site causing the enzyme to lose shape
• Makes the active site less effective/accessible
• Ex: toxins, poisons, pesticides, antibiotics

• Can either inhibit or stimulate an enzyme's activity
• Occurs when a regulatory molecule binds to a protein at one site and affects the proteins function at another

DO NOT bind to the active site of an enzyme

Bind to the enzyme and stabilize the active form

Bind to the enzyme and stabilize the inactive  form of the enzyme

• The end product of a metabolic pathway inhibits an enzyme in the pathway, shutting down the pathway
• Prevents a cell from wasting resources by synthesizing more product than is needed